1. Field of the Invention
This invention relates to a non-contacting-type information storing device, and more particularly, is suitably applied to a non-contacting-type commodity-identifying tag which is used in the process of distribution, stock control and such.
2. Description of the Related Art
A label printed a bar code indicating the stated identification data of a commodity (hereinafter, this is referred to as a bar-code label) has been used as a non-contacting type commodity-identifying tag of this kind; by reading the identification data written in the bar code, when necessary in the process of distribution, stock control and such, the commodity to which this bar-code label has been stuck can easily be identified.
In such a commodity identifying method that uses a bar-code label, because of very small storage capacity, 32 byte in general, of a bar code, the amount of information that can be allocated to one commodity is limited to, for instance, the identification (ID) number, manufacture data and such of the commodity. As a result, the applicability is limited to only simple systems of the process of distribution, stock control and such.
Therefore, recently, in complex systems of distribution process, stock control and such, a non-contacting-type tag that includes a memory integrated circuit (IC) is used as a, commodity-identifying tag (hereinafter, this is referred to as a memory-IC tag).
In comparison with a bar code label, a memory-IC tag has such higher storage capacity: 1k byte, that it is able to greatly increase the amount of information that can be allocated to one commodity; as a result, there is such an advantage that it is also applicable enough to complex systems of distribution process, stock control and such.
In addition, the data contents of a memory-IC tag can be rewritten any number of times; therefore, the memory-IC tag can be recycled efficiently: the memory-IC tag is peeled away from the commodity at the time of transportation or the time of sale, and then the identification data of the different commodity is newly written in it.
Practically, in the process of distribution, stock control and such, a data read/write system 1 shown in FIG. 1 is constructed so that the stated identification data is read from a memory-IC tag 3 stuck to a commodity 2, or new identification data is written in the memory-IC tag 3.
As the-memory-IC tag 3 that can be applied to such a data read/write system 1, there is one known wherein a memory IC 4 is built almost in the center of a substrate (hereinafter, this is referred to as a tag substrate) 3A that has a multi-layer structure for instance, and a wiring (hereinafter, this is referred to as a tag antenna) 5 is placed along the marginal inner side of the tag substrate 3A so that it forms a loop of an approximately square shape.
As shown in FIG. 2, the memory-IC tag 3 has an antenna board 3AA provided with a memory IC 4 almost in the center of its underside surface, and the tag antenna 5 extended from the memory IC 4 has been attached to the marginal inside portion of the surface.
To the under surface of this antenna board 3AA, a reinforcing plate 3AB made of polyethylene telephthalate (PET) is stuck, so as to protect the memory IC 4 and the tag antenna 5. This reinforcing plate 3AB has a thickness that is more than or equal to the height of the memory IC 4, and a penetrating hole 3ABH whose size is slightly larger than that of the memory IC is formed almost in the center of the reinforcing plate 3AB.
When the reinforcing plate 3AB has been stuck to the antenna substrate 3AA, the memory IC 4 is contained in the penetrating hole 3ABH of the reinforcing plate 3AB, and so the memory IC 4 is able to avoid jutting from the reinforcing plate 3AB.
One surface of a pressure-sensitive adhesive film 3AC is glued to the reinforcing plate 3AB; to the other surface of the pressure-sensitive adhesive film 3AC, a releasable paper 3AD is stuck in a manner that it can be peeled away as necessary. On the other hand, one surface of a pressure-sensitive adhesive film 3AE is glued to the top surface of the antenna substrate 3AA; to the other surface of the pressure-sensitive adhesive film 3AE, a cover paper 3AF is stuck.
Thus, the operator can write the characters, the signs and such regarding a commodity 2 on the cover paper 3AF that lies on one side of the tag cover 3A, and able to stick the memory-IC tag 3 on the surface of the commodity 2, by pressing the pressure-sensitive adhesive film 3AC onto the surface of the commodity 2 with the releasable paper 3AD peeled away from the other side of the tag substrate 3A.
A data read/write device 6 of the data read/write system 1 (FIG. 1) includes a read/write antenna division 7 for causing electromagnetic induction between itself and the memory-IC tag 3, and a read/write module 8 for sending and receiving various data via the read/write antenna division 7.
In the read/write antenna division 7, a loop coil of approximately square shape (hereinafter, this is referred to as a read/write antenna) 9 is formed on one side of a read/write antenna substrate 7A that is made from, for instance, glass epoxy resin material, so that its position corresponds to the position of the tag antenna 5 formed in the memory-IC tag 3, when it is opposed to the memory-IC tag 3.
One end and the other end of this read/write antenna 9 are connected to the read/write module 8 via a connector 10 and a harness 11 in succession. In a state that the read/write antenna division 7 is opposed to the memory-IC tag 3, the read/write module 8 feeds a current to the read/write antenna 9 from the stated AC power supply, via the harness 11 and the connector 10 in succession.
As a result, a magnetic field modulated in response to the change of the given current is generated around the read/write antenna 9, so that an induction voltage is generated in the tag antenna 5 that is formed in the memory-IC tag 3 in response to the modulated magnetic-field. The degree of coupling of electromagnetic induction concerning the read/write antenna 9 and the tag antenna 5 of this time varies in response to the mutual relationship of position.
The memory IC 4 rectifies the induction voltage inputted through the tag antenna 5, and then performs reading or writing of the identification data on the basis of the AC components that appear in the obtained voltage.
After rectification of the induction voltage inputted via the tag antenna 5, the memory IC 4 is able to obtain power-supply voltage on the basis of the DC components that appear in the obtained voltage, and so able to start up in response to the power-supply voltage even though a power source such as a battery is not provided in the memory-IC tag 3.
When the identification data is read, in the memory-IC tag 3, by mutual induction, a modulated magnetic-field is generated from the tag antenna 5 to the read/write antenna 9, such that it cancels the modulated magnetic-field generated from the read/write antenna 9 to the tag antenna 5.
At this time, because the input impedance between the both terminals of the tag antenna 5 varies in response to the identification data that has been read from the memory IC 4, the varied amount is added to the modulated magnetic-field that generate from the tag antenna 5 to the read/write antenna 9.
Hence, the impedance between the both terminals of the read/write antenna 9 which is opposed to the tag antenna 5 varies in like manner, and so the induction voltage generated in the read/write antenna 9 also varies to the same extent. Therefore, by demodulating the generated varied amount of the induction voltage, the read/write module 8 is able to read the identification data obtained from the memory IC 4.
However, when such a memory-IC tag 3 is stuck on the adherent surface 2 A made of metal of a commodity 2 and then the identification data is read from the memory-IC tag 3 by the use of said data read/write device 6, the modulated magnetic-field MF generated from the read/write antenna 9 is absorbed by the adherent surface 2 A of the commodity 2 without reaching the tag antenna 5. On the other hand, part of the modulated magnetic-field MF that has passed through the tag board 3 A is reflected by the adherent surface 2 A so that it might cancel the magnetic field, as shown in FIG. 3. As a result, there has been a fear that the sufficient electric power can not be supplied to the memory IC 4 in the memory-IC tag 3.
As a result, there has been a problem that the identification data can not be read from the memory IC 4 included in the memory-IC tag 3. In the case where the adherent surface 2A of the commodity 2 is made of metal, the memory-IC tag 3 can not be applied.
In view of the foregoing, an object of this invention is to provide a non-contacting-type information storing device that is able to read information irrespective of the type of the material of the adherent surface of the object.
The foregoing object and other objects of the invention have been achieved by the provision of a non-contacting-type information storing device which is stuck to the adherent surface of an object, having an information storing means storing therein prescribed information on the object and an antenna in a loop form connected to the information storing means, and reads out and writes the prescribed information in the information storing means via the antenna in response to a modulated magnetic-field given from the exterior. The non-contacting-type information storing device comprises: a substrate having the information storing means and the antenna; a magnetism absorbing member made from high-permeable material, provided between the substrate and an adherent surface of the object, and having an area at least enough to cover the antenna provided on the substrate; an adhesive member gluing the substrate and the magnetism absorbing member; and a gluing member gluing the magnetism absorbing member on the adherent surface of the object.
Also, in the non-contacting-type information storing device according to the present invention, the substrate and the magnetism absorbing member are integrated by the adhesive member, and the gluing member is provided on the magnetism absorbing member integrated with the substrate.
Further, in the non-contacting-type information storing device according to the present invention, the adhesive member is provided on the substrate, the gluing material is provided on the magnetism absorbing member, the substrate provided with the adhesive member and the magnetism absorbing member provided with the gluing member are composed as individual units, and the substrate provided with the adhesive member and the magnetism absorbing member provided with the gluing member are integrated when being glued on the adherent surface of the object.
In addition, in the present invention, the magnetism absorbing member is made from high-permeable material whose permeability is 10 or more.
As described above, the present invention provides a magnetism absorbing plate which is made of high-permeable member and which has been placed so that it is interposed between the adherent surface of the object and the antenna at the time when the information storing device is stuck to the adherent surface of the object. As a result, it is possible to provide a non-contacting-type information storing device that the modulated magnetic-field given from the exterior can be absorbed by the antenna without being leaked toward the adherent surface of the object even though the adherent surface of the object is made of metal, Thus, the information can be read irrespective of the type of the material of the adherent surface of the object.
The nature, principle and utility of the invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings in which like parts are designated by like reference numerals or characters.